This blog features my weekly column called "What's up in the sky". It is published every Saturday in the Ellensburg newspaper, Daily Record (http://www.kvnews.com/). While my postings will be most accurate for Central Washington, readers throughout the northern USA may find something of use.

Friday, September 27, 2013

Saturday:
Mnemonics are helpful for remembering astronomy facts. (Similarly, “Johnny
Mnemonic”, the 1995 cyberpunk film, was helpful in getting Keanu Reeves’ career
going.) After all, school children all around the country are learning the
order of the planets by remembering, “My very excellent mother just served us
nine….” Oops, I guess that one needs updating. Well, here’s one that will not
need updating for nearly 100,000 years: the order of the stars in the Big
Dipper. Because the nighttime stars are so far away from us, their actual
motion through the sky, called their “proper motion” is not noticeable over
even thousands of years. That is why the constellations have remained the same
since ancient times. But two stars in the Big Dipper have a proper motion large
enough such than in 100,000 years, the stars will no longer make a dipper
shape. Until then, you can remember the names of the seven dipper stars in order
from handle to cup by remembering this helpful advice for teens: “AM, ask mom.
PM, dad”. The stars are Alkaid, Mizar, Alioth, Megrez, Phad, Merek, and Duhbe.
The Big Dipper is one fist held upright and at arm’s length above the north
horizon at 11 p.m.

Sunday: To
the people of Ancient Greece, the stars that are about five and a half fists
above the east-northeast horizon at 10 p.m. were known as Cassiopeia and
Andromeda, a mythological queen and her daughter. But not all cultures imagined
the same pictures in the sky. To the people of Polynesia, the stars of
Cassiopeia and Andromeda represented a dolphin, called Kwu. Cassiopeia formed
its tail, the brightest stars of Andromeda formed its fins, and its fainter
stars outlined the dolphin’s body.

Monday: Three
planets are crowded around the setting Sun. Venus, the brightest, is one fist
above the southwest horizon. Saturn is about a fist and a half to the right of
Venus. Mercury is below Saturn, just barely above the horizon.

Tuesday: Uranus
is in opposition tonight. That doesn’t mean that Uranus is in the minority
party in the senate. Opposition means that Uranus is on the opposite side of
the Earth as the Sun. When an object is in opposition, it is at its highest
point in the sky during the darkest time of the day. Thus, opposition is
typically the best time to observe a planet. Uranus is about four and a half
fists above the south horizon at 1 a.m. It is three and a half fists above the
southeast horizon at 10:30 p.m. You’ll need binoculars to find it. First find
Deneb Kaitos, the brightest star in the constellation Cetus the sea monster, one
and a half fists above the southeast horizon. Deneb Kaitos is the same
brightness as the North Star. If you imagine the distance from the horizon to Deneb
Kaitos as one unit, move your binoculars straight up from southwest two more of
those units. Uranus will be in the center of your field of view. Check that
same spot over the next few night. Uranus will move slightly with respect to
the distant stars.

Wednesday:
Mars is about to get eaten by a lion, a constellation lion. It is right in
front of the head of Leo the lion, three fists above the east horizon at 6 a.m.

Thursday: Keep
an eye out for Jupiter which is slowly creeping into the pre-midnight sky.
Tonight it rises at about 11:45 p.m. By 12:30, it is a half a fist above the
east-northeast horizon.

Friday: The
constellation Orion is four fists above the south horizon at 6 a.m. The Orion
is a cloud of gas and dust visible with binoculars about a half a fist below
the “belt” of three stars. If you are feeling especially attracted to the
nebula, that might be because astronomers think there may be a black hole in
the middle. They have not directly observed the back hole, which would be the
closest known one to Earth at a distance of 1,300 light years. But the motion
of stars in the region is consistent with them being near a black hole 100
times the mass of the Sun. For more information, go to http://goo.gl/AGjFf.

The
positional information in this column about stars and planets is typically
accurate for the entire week.

Wednesday, September 18, 2013

Saturday: “You
know Aries and Cancer and Draco and Libra. Leo and Pisces and Virgo and Hydra.
But, do you recall, the pointiest asterism of all? Triangulum, the three sided
asterism, had a very pointy edge….” Sorry. Some stores have started putting up
their Christmas decorations and that has put me in the mood to modify some
Christmas songs. Anyway, Triangulum is a small constellation between the more
prominent Andromeda and Aries. Its main feature is a skinny triangle oriented
parallel to and nearly four fists held upright and at arm’s length above the
east horizon at 10 p.m.

Sunday: At
precisely 1:44 p.m. PDT, the center of the Sun crosses the celestial equator
and passes into the southern sky. The celestial equator is an imaginary line
that divides the sky into a northern and southern half. When the Sun is in the
southern half of the sky, it appears to take a shorter path from rising to
setting. It also does not get as high in the sky at noon. This leads to shorter
days and longer nights. Since the Sun crosses the celestial equator today,
there is an instant when it is equally in the northern and southern sky, called
the north and south celestial hemispheres. This so-called “equal night” is
given by the Latin word equinox. Thus, today is known as the Autumnal Equinox.
However, the day and night are not of equal duration today. The sun rises at
6:50 a.m. and sets at 6:58 p.m. Day and night are closest to equal duration on
Tuesday.

Monday: “My
laddie, you’re a wee bit close to that launch” is what a stereotypical Scottish
person may have said to a frog that watched the recent launch of the Lunar
Atmosphere and Dust Environment Explorer. The spacecraft, abbreviated LADEE and
pronounced “laddie”, was launched on September 6. A remote NASA camera captured
an image of a frog jumping at the same time the rocket blasted off. Read more
about the launch, and more importantly, the frog at http://goo.gl/YrwkpU. LADEE’s mission is to
study the moon’s very thin atmosphere and conditions near the moon’s surface.

Tuesday:
To celebrate the start of school at CWU tomorrow, let’s sing a song of the
season. “Oh the weather outside is grand. And the fire is rightfully banned.
There is really no place to go. Let it snow, let it snow, let it snow. On
Mars.” The Mars Reconnaissance Orbiter has discovered evidence of carbon
dioxide snow clouds high above the surface of Mars.Carbon dioxide, also called “dry ice”, exists in Mars south
polar ice cap and requires temperatures of nearly 200 degrees below zero Fahrenheit
to form. Astronomers were not sure how this polar cap gets replenished but the
discovery of carbon dioxide clouds may provide an answer. For more information,
go to http://goo.gl/shMTf. Mars is three
fists above the east-southeast horizon at 6 a.m. The weather is certainly not
grand on Jupiter, which you can find five and a half fists above the southeast
horizon at this time.

Wednesday: Did you time the exact length of the day and night on
Saturday, the first day of autumn? They were not equal in duration. Many people
think that the day and night are the same duration on the autumnal equinox. The
day is a little longer than the night for two reasons. First, the Sun is an
extended object so even when the middle part has set, the upper half is still
above the horizon lighting the sky. The second, and more influential reason is
that the atmosphere acts like a lens, bending light from the Sun above the
horizon when the Sun is really still below the horizon. Day and night are
closest in duration today.

Friday: The
cloudy season is coming to Ellensburg. Don’t feel bad. According to astronomers
from the European Southern Observatory, it is always cloudy season on HD
85512b, a newly discovered planet orbiting the star called… wait for it… wait
for it… called HD 85512. These astronomers developed a method to estimate the
cloud cover on planets orbiting distant stars. They think HD 85512b may be
cloudy enough to have liquid water on its surface even though it is fairly
close to its host star. While the presence of surface water does not guarantee
finding life, it is a critical component. For more information, go to http://goo.gl/bGxMD.

The
positional information in this column about stars and planets is typically
accurate for the entire week.

Wednesday, September 11, 2013

You can
use the orientation of the Big Dipper to tell time with a precision of about
15-30 minutes. First, find the two stars at the far end of the Big Dipper cup,
the stars that do not touch the handle. Draw an imaginary line segment starting
at the North Star and passing through the two Big Dipper cup stars. Now, draw a
big circle around the North Star. Your circle is a 24-hour clock. Number the
circle from 0 hours at the top, counterclockwise to 12 hours at the bottom of
the circle, and back up to 24 hours at the top. (O hours and 24 hours are the
same on this clock because the day is 24 hours long.) The hour number on the
big circle closest to where your imaginary line intersects this circle is called
your raw time. Due to the location of the Big Dipper compared to the rest of
the stars, the time nearest the intersection (the raw time) is correct for
March 6. For any other night, subtract two times the number of months the
current date is after March 6 from the raw time. For example, let’s say the
imaginary line between the North Star and the Dipper stars is pointed to the
right. That means the raw time is 18 hours or 6 p.m. If you made this
observation on October 6, which is seven months after March 6, you would
subtract two times seven or 14 hours from the raw time.Thus, the time for November 6 is 18
hours minus 14 hours or 4 hours. In other words, 4 a.m. Don’t forget to convert
for daylight savings time if needed. For a more complete set of instructions,
go to http://goo.gl/02HmA. There is a simple “star clock” template and
instructions at http://goo.gl/SFKrE. Use this paper star clock whenever you
watch is broken.

Sunday: Venus
and Saturn are close together in the early evening sky for the next few days.
At 8 p.m., Venus is about a half a fist held upright and at arm’s length above
the west-southwest horizon. Saturn is less than a half a fist to the upper left
of Venus. Over the next few evenings, Saturn will move down toward Venus in the
sky.

Monday: Let
me tell you the story of the ghostly white figure that rises early in the
morning in early autumn. It appears to be a huge dim glow of white light that
rises up from the east in the pre-dawn sky. No, I’m not writing about the ROTC
student who has early morning physical training. I’m describing an effect
called the zodiacal light. This light comes from sunlight reflecting off dust
grains in our solar system. The effect is the most visible when the band of
constellations called the zodiac makes a steep angle with the horizon. You need
a clear sky with no haze or light pollution to see the zodiacal light that will
be visible for the next few weeks or so. At its brightest, the zodiacal light
rivals the light of the central Milky Way.

Tuesday: If
you stay up late, you can see Jupiter rising just before 1 a.m. If you get up
early, say 6 a.m., you can see Jupiter five fists above the east-southeast
horizon and Mars three fists above the eastern horizon.

Wednesday:
Shine on, shine on harvest moon, up in the sky. It’s just like a full moon in
January, February, June and July. The only difference is that near the Autumnal
Equinox (also known as the first day of fall), the full moon rises close to
sunset resulting in a full night of light for the harvest. The harvest moon
looks more orange than usual when it is near the horizon because of the dust
kicked up from the harvest. The dust scatters the white light reflecting off of
the Moon resulting in slightly more of the red and orange components of the
white light reaching your eyes. Although the Moon has a dull yellow color
whenever it is near the horizon owing to light scattering off of dust and
atmospheric particles, the effect is more noticeable for the harvest Moon.
Tonight’s full moon, which isn’t completely full until tomorrow at 4 a.m., is
in the constellation Pisces the fish. For more information about the harvest
moon, go to http://earthsky.org/space/harvest-moon-2.

Thursday: “One
world, group hug, love everyone” philosophy: political borders are human-made
and can’t be seen from space. Real world, pragmatic discovery: some human-made
political borders CAN be seen from space. Since 2003, India has illuminated its
border with Pakistan to prevent illegal crossings. In August, astronaut Ron
Garan took a picture of the boarder from the International Space Station. For
more information, including the photo, go to http://goo.gl/mY8xG.

Friday: Sirius,
the brightest star in the nighttime sky, is two fists above the southeast
horizon at 6 a.m.

The
positional information in this column about stars and planets is typically
accurate for the entire week.

Tuesday, September 3, 2013

Saturday: Are
you an early morning riser? If so, get up at 5 a.m. tomorrow morning and look
two fists held upright and at arm’s length above the east horizon. Mars is in
the Beehive Cluster, an open cluster of about 600 stars, all about 600 light-years
from Earth. If you were standing on Mars, the Beehive cluster would not look
any different because being “in” a celestial grouping just means being in line
with that grouping as viewed from Earth. But if you were standing next to the
Mars Curiosity Rover on August 17, you would have seen Mars’ moon Phobos
eclipse the Sun. Since Mars tickets are difficult to acquire, NASA made a short
video for you http://goo.gl/79sr59.

Sunday: Geometry
review, part 4. Previously in this column, we have reviewed triangles. You’re
feeling pretty confident about the definition of a triangle, aren’t you? But do
you know what an obtuse triangle is? At 8 p.m., the moon, Venus, and Spica will
make a small obtuse triangle about a half a fist above the west-southwest
horizon. A triangle where one of the interior angles is greater that 90 degrees
is called obtuse.

Monday: Science
is Central! This week, faculty, staff, and students in the College of the
Sciences at CWU will kick off the start of the academic year by hosting a
series of evening science lectures and demonstrations geared for all ages. All
events are taking place on the CWU Ellensburg campus and all are free. The
series kicks off tonight with CWU professor, astronomy club advisor and
columnist extraordinaire Bruce Palmquist at 7:00 – 8:00 pm in Lind Hall 215 on
the CWU campus. He’ll be doing and teaching demonstrations about electricity
and magnetism. They’ll make you say, “Wow”, Ohhh”, and “Ahhh”. Go to http://www.cwu.edu/newmap.html for a map
of campus. Parking is free after 4:30 p.m. For more information about the
week’s events, go to http://www.cwu.edu/cesme/upcoming-events.

Tuesday:
In most parts of the country, a mixture of tasty carbon-based material and
healthy minerals is called a casserole. In Minnesota, it is called a hot dish.
(Uffdah, you betcha!) In space, it is called a supergiant. Antares, a
supergiant in the constellation Scorpius, is forging lighter elements into
carbon, oxygen, silicon, and iron in its core. It is on the main course table
one fist above the southwest horizon at 7:30. Make sure it cools off before you
take a bite.

Wednesday:
Saturn is one fist above the southwest horizon at 8 p.m. It is to the upper
left of the much brighter Venus.

Thursday:
In 1987, the rock group Def Leppard sang “Pour some sugar on me, in the name of
love. Pour some sugar on me, come on fire me up”. In 2012, some European
astronomers “found some sugar near stars, they were very young. Found some
sugar near stars, out where planets formed.” Astronomers observed molecules of
glycolaldehyde, a simple form of sugar, in the disk of gas and dust orbiting
young binary stars. This is the first time astronomers have found this simple
sugar so close to a star indicating that organic molecules can be found in
planet-forming regions of stars. For more information, go to
http://goo.gl/tfwy1.

Friday: Did
you know that Friday the 13th is not a lucky day? “Beating the odds” is one
definition of luck. Because of the pattern of the Gregorian calendar, Friday is
the most common day of the week to be the 13th day of the month. Thus, when you
encounter a Friday the 13th, you are not beating the odds because Friday is the
most likely 13th day. The least likely day? A tie between Thursday and
Saturday.

The
positional information in this column about stars and planets is typically accurate
for the entire week.